Italy 2004 - Foundation of Rome and Bangkok on 21st April

A joint issue (in a souvenir sheet only in Italy) to celebrate the cities of Rome and Bangkok on the common day of their foundation, the 21st of April.  

Rome is believed to have been founded in 752 or 753BC.

Bangkok was founded in 1782, when it was moved to the eastern bank of the Chao Phraya River by King Buddha Yodfa Chulaloke.  The stamp shows the 18th Century temple of Wat Saket, the Golden Mount.

The same were issued in Thailand, both as single stamps and as the souvenir sheet.   

Source:  http://www.jointstampissues.net/new_issues/news2004_01_04.htm.